The invention relates to an assembly for supporting a wheel of a motor vehicle and for drivingly connecting the wheel to a driveshaft, comprising a wheel carrier which is attachable to the motor vehicle and is provided with an annular part and a plurality of steering arms; a wheel hub which is rotatably supported in the annular part of the wheel carrier and is provided with a flange for bolting on the wheel; a rolling contact bearing with two rows of rolling contact members for supporting the wheel hub in the wheel carrier, which rolling contact bearing is insertable into the annular part of the wheel carrier; and a constant velocity joint which comprises an outer joint part removably connectable to the wheel hub, and an inner joint part connectable to the driveshaft, wherein the connection between the wheel hub and the outer joint part is provided by inter-engaging toothings of which a first toothing is formed at a part of the wheel hub and wherein a second toothing is formed at a sleeve projection at the outer joint part, and wherein the inter-engaging toothings are axially secured by a securing ring which engages two annular grooves of which a first annular groove is formed at said part of the wheel hub in the region of the first toothing and wherein a second annular groove is provided at the sleeve projection in the region of the second toothing.
From WO 99/13232 there is known a unit of said type wherein, for assembly purposes, the securing ring is inserted into the annular groove on the wheel hub and is contracted by means of a clamp in such a way that it is positioned fully within the base diameter of the toothing or wherein the securing ring is inserted into the annular groove in the outer joint part and expanded by means of a wedge in such a way that it is positioned fully outside the base diameter of the toothing. Thereafter, the counter piece is mounted, i.e. the outer joint part is slid on or the wheel hub slid in until the annular groove provided therein axially overlaps with the securing ring, and the clamp or wedge is radially outwardly removed. In the process, the securing ring expands so that it also engages the annular groove in the outer joint part, or the securing ring contracts, so that it also engages the annular groove in the wheel hub. In both embodiments, there is provided a notch at the end of the outer joint part, which notch accommodates the clamp or wedge as well as radially bent ends of the securing ring. To render the securing ring manipulatable in connection with removing the clamp or wedge, with the wheel hub being mounted in the wheel carrier, the wheel carrier is provided with a radial bore which is positioned so as to axially correspond to the annular grooves or, respectively, to the notch in the outer joint part, permitting access to a tongue projection at the clamp or wedge from the outside of the wheel carrier. Once the assembly of the unit has been completed by removing the clamp or wedge, dismantling is possible only by destroying the securing ring by applying axial forces between the wheel hub and outer joint part.
DE 197 00 313 A1 proposes an assembly of said type wherein the securing ring is provided in the form of a snap ring which automatically engages the inner groove in the inner toothing of the outer joint part. Such an assembly cannot be dismantled in a non-destructive way. On the contrary, when the wheel hub unit and the constant velocity joint are forcibly removed in the axial direction, the securing ring is squashed and the toothings may be damaged at the same time. From DE 197 51 855 C1, there is known an assembly of the initially mentioned type wherein the securing ring is freely radially accessible from the outside and is positioned axially relative to the joint end, in front of the annular part of the wheel carrier. For this purpose, the wheel hub is connected to a driving ring which carries the respective toothing to achieve toothing engagement with the outer joint part, which driving ring is axially extended beyond the hub end. This increases the overall length of the assembly, as a result of which simultaneously available length for the driveshaft is lost, with the constant velocity joint forming part of said driveshaft. Said length represents a particularly critical aspect because shortening the driveshaft with predetermined maximum joint angles goes hand in hand with a reduction in the steering angles and spring travel.
It is an object of the present invention to further develop an assembly of said type in such a way as to facilitate the assembly and dismantling of the constant velocity joint and simultaneously to improve the ability to replace driveshafts in motor vehicles. A first solution consists in that, at the wheel carrier, in the annular part, in at least one circumferential position, there is provided a broken-out portion which axially cuts into the annular part from the wheel end and that, with a rolling contact bearing secured in the wheel carrier and with an outer joint part connected to the wheel hub, the two annular grooves are positioned so as to axially correspond to the broken-out portion, and the securing ring can be handled by pliers through the broken-out portion. A second solution consists in that, at the wheel carrier, in the annular part, in at least one circumferential position, there is provided a broken-out portion which axially cuts into the annular part from the joint end and that, with a rolling contact bearing secured in the wheel carrier and with an outer joint part connected to the wheel hub, the two annular grooves are positioned so as to axially correspond to the broken-out portion, so that the securing ring can be handled by pliers through the broken-out portion. The means described here allow a driveshaft to be assembled and dismantled in a non-destructive way without there being any need for the vehicle wheel to be removed from the wheel hub or for the wheel hub to be removed from the wheel carrier and without the wheel carrier having to be removed in any way from the vehicle. The plunging distance required for the assembling and dismantling operations and for releasing the inter-engaging toothings necessarily exists design-based in the constant velocity joint at the differential end. Without substantially adversely affecting the strength of the annular member, the design of the broken-out portion permits the necessary access to the securing ring. For this purpose, the shaft with the outer joint part has to be moved into a rotational position in which, in a radial view, the ends of the securing ring come to rest below the notch, and the securing ring, again in an axial view, is positioned inside the longitudinal extension of the broken- out portion.
It is the object of the present invention to further develop an assembly of said type in such a way as to facilitate the assembly and dismantling of the constant velocity joint and simultaneously to improve the ability to replace driveshafts in motor vehicles. A first solution consists in that, at the wheel carrier, in the annular part, in at least one circumferential position, there is provided a broken-out portion which axially cuts into the annular part from the wheel end and that, with a rolling contact bearing secured in the wheel carrier and with an outer joint part connected to the wheel hub, the two annular grooves are positioned so as to axially correspond to the broken-out portion, and the securing ring can be handled by pliers through the broken-out portion. A second solution consists in that, at the wheel carrier, in the annular part, in at least one circumferential position, there is provided a broken-out portion which axially cuts into the annular part from the joint end and that, with a rolling contact bearing secured in the wheel carrier and with an outer joint part connected to the wheel hub, the two annular grooves are positioned so as to axially correspond to the broken-out portion, so that the securing ring can be handled by pliers through the broken-out portion. The means described here allow a driveshaft to be assembled and dismantled in a non-destructive way without there being any need for the vehicle wheel to be removed from the wheel hub or for the wheel hub to be removed from the wheel carrier and without the wheel carrier having to be removed in any way from the vehicle. The plunging distance required for the assembling and dismantling operations and for releasing the inter-engaging toothings necessarily exists design-based in the constant velocity joint at the differential end. Without substantially adversely affecting the strength of the annular member, the design of the broken-out portion permits the necessary access to the securing ring. For this purpose, the shaft with the outer joint part has to be moved into a rotational position in which, in a radial view, the ends of the securing ring come to rest below the notch, and the securing ring, again in an axial view, is positioned inside the longitudinal extension of the broken-out portion.
According to an advantageous embodiment for both solutions, it is proposed that, in the circumferential direction, directly on both sides of the broken-out portion, there are provided bolting means between the annular part of the wheel carrier and the outer bearing race of the rolling contact bearing. In this way, the reduction in material at the annular member resulting from the broken-out portion is compensated for by the connection between the annular member and the outer bearing race.
According to an advantageous embodiment of the second solution, it is proposed that the broken-out portion is positioned in the region of a steering arm into which it cuts radially. In this case, too, the reduction in material at the annular member resulting from the broken-out portion is compensated for by the bridging function of the steering arm.
In order to exclude load peaks and to ensure a harmonious curve of forces, the broken-out portion, in an axial view, is substantially U-shaped or optionally substantially U-shaped in an axial view.
In a preferred embodiment, the toothings at the sleeve projection and at the wheel hub are provided in the form of inter-engaging hub and shaft toothings and, at the sleeve projection in the region of the hub toothing, there is provided a circumferentially delimited and axially delimited notch which interrupts the second annular groove and which, with an outer joint part connected to the wheel hub, exposes the first annular groove in the shaft toothing of the wheel hub and the securing ring in a circumferentially delimited way. The ends of the securing ring are then able to engage the notch and support themselves thereon in the circumferential direction. The ends of the securing ring projecting outwardly from the notch are accessible through the broken-out portion for assembling and dismantling purposes.
According to a further solution wherein, at the sleeve projection, in the region of the toothing, there is provided a circumferentially delimited and axially delimited notch which interrupts the second annular groove and which, with the outer joint part connected to the wheel hub, exposes the first annular groove and the securing ring in a circumferentially delimited way, wherein an approximately radially extending bore is provided at the wheel carrier in the annular part and wherein, with the rolling contact bearing secured in the wheel carrier and with the outer joint part connected to the wheel hub, the two annular grooves are positioned so as to axially correspond to the bore, it is proposed that the diameter d of the bore is smaller than or equal to the circumferential extension b of the notch and that the securing ring can be handled by pliers through the bore. The means described here allow a driveshaft to be assembled and dismantled in a non-destructive way without there being any need for the vehicle wheel to be removed from the wheel hub or for the wheel hub to be removed from the wheel carrier and without the wheel carrier having to be removed in any way from the vehicle. The plunging distance required for the assembling and dismantling operations and for releasing the inter-engaging toothings necessarily exists design-based in the constant velocity joint at the differential end. In spite of reducing the size of the bore relative to the circumferential extension of the notch, the securing ring can be gripped in a conventional way by pliers.
According to an advantageous embodiment, it is proposed that the axial depth t of the notch is smaller than the diameter d of the bore. In this way it is ensured that the outer joint part is weakened as little as possible by the notch. At the same time it is ensured that outwardly bent ends of the securing ring engage the notch and act as anti-rotation means relative thereto.
After the assembly has been assembled and mounted, the bore can be used for receiving an ABS sensor. For this purpose, a pulse generating ring has to be arranged in the direct vicinity of the securing ring, for example on the outer joint part.
For production reasons it is advantageous if the first toothing at the hub member is provided at a separate driving ring which is slid on to the wheel hub and non-removably secured thereto. To prevent any rotation between said two parts, these, in turn, can be provided with inter-engaging longitudinal toothings. The driving ring can be axially secured on the wheel hub, in particular, by hub member beading. The driving ring can axially rest against an inner bearing race of a first row of rolling contact members, which bearing race is also slid on to the hub member and which, at the same time, is clamped by the driving ring against an inner bearing race of a second row of rolling contact members. As a rule, the second inner bearing race is formed directly from the hub member.
In an advantageous way, the subject of the present invention provides a short assembly of said type which, by simple means and in a non-destructive way and without removing the wheel carrier unit and the wheel hub unit, can be separated from the constant velocity joint of a driveshaft. At the same time the invention ensures easy accessibility for assembly purposes without substantially reducing the strength of the assemblies. In an advantageous way, the subject of the present invention provides a short assembly of said type which, by simple means and in a non-destructive way and without removing the wheel carrier unit and the wheel hub unit, can be separated from the constant velocity joint of a driveshaft. At the same time the invention ensures easy accessibility for assembly purposes without substantially reducing the strength of the assemblies.